Vulnerability Update: Intel CPU Branch Privilege Injection Flaw
CVE: CVE-2024-45332
Timeline: Disclosure date remains 2024-05-13. Intel released microcode updates after receiving the report in September 2024. Full technical details will be presented at USENIX Security 2025.
exploitMaturity: Remains at Proof-of-Concept, with detailed exploit demonstration by ETH Zurich researchers and no known real-world exploit reported by Intel so far.
affectedVersions: The affected versions remain Intel CPUs from the 9th generation onward (Coffee Lake, Comet Lake, Rocket Lake, Alder Lake, Raptor Lake), with possible prediction bypass on processors as old as 7th generation (Kaby Lake). New information clarifies older generations lack certain mitigations making them less relevant to this specific exploit. Also, Arm Cortex-X1, Cortex-A76, and AMD Zen 4 and Zen 5 chips are not vulnerable.
fixedVersions: Mitigations include microcode updates released by Intel, firmware-level mitigations (with approx. 2.7% performance overhead), and software mitigations (with 1.6% to 8.3% performance impact, depending on CPU). Users are advised to apply BIOS/UEFI and OS updates.
Summary:
CVE-2024-45332 is a critical vulnerability affecting modern Intel CPUs that allows leakage of sensitive privileged data due to branch predictor race conditions. While core details remain consistent, this update brings enhanced technical depth, confirms affected versions, and details mitigation impacts. Exploit maturity remains proof-of-concept with no known widespread attack.
Description:
The vulnerability is a race condition flaw in modern Intel CPUs' branch predictors that allows non-privileged users to leak sensitive privileged memory data through speculative execution. The updated description provides more technical detail on the asynchronous predictor update and the specifically exploited branch predictors (BTB and IBP), and emphasizes the exploit demonstration on Ubuntu 24.04 with default mitigations enabled. Leak rates of up to 5.6 KB/sec at 99.8% accuracy have been observed.
Impact Scope:
Recommended Actions:
- Apply latest BIOS/UEFI updates
- Apply OS updates
- Be aware of performance impact: firmware mitigations ~2.7% overhead; software mitigations 1.6% to 8.3% depending on CPU
Related Resources:
- https://t.co/QZjcXRK5xA
- https://t.co/lQ1aX4CQMs
Tags: #CPU #DataLeak #Intel #Processor #SideChannelAttack #SpeculativeExecution #SpeculativeExecutionSideChannel #Cybersecurity
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